temp gauge and radiator temp disagree - Third Generation F-Body Message Boards


Cooling Discuss all of the aspects of cooling that you can think of! Radiators, transmissions, electric fans, etc.

temp gauge and radiator temp disagree

Reply
 
Thread Tools Search this Thread
Old 07-13-2018, 05:40 PM   #1  
Supreme Member
Thread Starter
 
Join Date: Feb 2004
Location: Munster IN
Posts: 1,158
Car: 92 RS, 05 GTO (sold), 10 TL AWD
Engine: 383 HSR w/DSC1
Transmission: 700r4
Axle/Gears: Strange S60/3.73


temp gauge and radiator temp disagree

so I am running a holley HP efi setup and I am having some cooling issues. It is a highly custom 383 with a procharger. Car is running original v8 radiator and tpi dual fans.

now the car sat in my garage for about 10 years and now money/time/interest have got me back into it. the temp gauge in the cluster and the direct CTS readout on my laptop both agree the engine coolant temp just keeps running north. I'm not talking about high throttle driving, just 25mph in my subdivision. The factory radiatior should be capable of dealing with that as the engine is only make a hundred some horsepower (if that) in that situation. What I find interesting is I put a temp gauge radiator cap on and when the CTS is reading 220, the rad gauge only reads 200. Is this a flow issue? The upper rad hose is hot and clearly flowing as its firm. Just wondering if the issue I am seeing is a function of limited flow. The cap gauge seems to be accurate with room temp when the car is cold.

Thought?
1992rs/ss is offline   Reply With Quote
Old 07-13-2018, 07:32 PM   #2  
Supreme Member
 
NoEmissions84TA's Avatar
 
Join Date: Feb 2017
Location: Meriden, CT 06450
Posts: 1,750
Car: 84 TA orig. 305 LG4 "H" E4ME
Engine: 334 SBC - stroked 305 M4ME Q-Jet
Transmission: upgraded 700R4 3200 stall
Axle/Gears: 10 bolt 4.10 Auburn Posi

Re: temp gauge and radiator temp disagree

Did all the readings agree 10 years ago? Is this with 10 year old coolant?
A lot can happen while sitting for 10 years. Dead coolant, electrolysis, & corrosion come to mind.
Give it a good flush and replace the coolant for starters.
NoEmissions84TA is offline   Reply With Quote
Old 07-13-2018, 10:34 PM   #3  
Supreme Member
 
W.E.G.'s Avatar
 
Join Date: Dec 2012
Location: northern VA
Posts: 1,313
Car: 88 Sport Coupe Camaro
Engine: V6 2.8
Transmission: Borg-Warner T-5
Axle/Gears: RPO/GU6: 3.42

Re: temp gauge and radiator temp disagree

In my car, the gauge will read 260, while the ECM is telling TunerPro the temp is 170.

A laser temp gauge on the upper radiator hose reads 210.
W.E.G. is offline   Reply With Quote
Old 07-14-2018, 11:49 AM   #4  
Supreme Member
Thread Starter
 
Join Date: Feb 2004
Location: Munster IN
Posts: 1,158
Car: 92 RS, 05 GTO (sold), 10 TL AWD
Engine: 383 HSR w/DSC1
Transmission: 700r4
Axle/Gears: Strange S60/3.73


Re: temp gauge and radiator temp disagree

The radiator was drained and refilled during the rebuild, but it was never "flushed". Coolant did sit in the system for 10 years. The temp gauge and the lap top agree on readout which makes me believe the engine is continuing to heat. I will try and flush it this week to see if it at least makes them agree.
1992rs/ss is offline   Reply With Quote
Old 07-14-2018, 12:33 PM   #5  
Supreme Member
 
Join Date: Oct 2004
Location: Henrietta NY
Posts: 3,733
Car: 1984 Trans Am L69
Engine: 355 Carbed V8 Patriot Vortec Heads
Transmission: WC T5 w/ Steel Support Plate
Axle/Gears: 3.42 10 Bolt Posi


Re: temp gauge and radiator temp disagree

My factory gauge read ~270 when my factory fan kicked on at 235. I verified 235 with an IR gun and aftermarket gauge. Now I have a 212F fan switch the factory gauge reads about 230 when that comes on where aftermarket is 210.
midias is offline   Reply With Quote
Old 07-14-2018, 06:40 PM   #6  
Supreme Member
 
NoEmissions84TA's Avatar
 
Join Date: Feb 2017
Location: Meriden, CT 06450
Posts: 1,750
Car: 84 TA orig. 305 LG4 "H" E4ME
Engine: 334 SBC - stroked 305 M4ME Q-Jet
Transmission: upgraded 700R4 3200 stall
Axle/Gears: 10 bolt 4.10 Auburn Posi

Re: temp gauge and radiator temp disagree

Quote:
Originally Posted by 1992rs/ss View Post
The radiator was drained and refilled during the rebuild, but it was never "flushed". Coolant did sit in the system for 10 years. The temp gauge and the lap top agree on readout which makes me believe the engine is continuing to heat. I will try and flush it this week to see if it at least makes them agree.
An old school radiator shop told me years ago to use Lestoil and water to flush, and do a flush with baking soda to neutralize any acids. Do it as many times as needed to come clean. It is summer now, so you can drive around for a couple of days with the Lestoil and then rinse without fear of freezing temperatures and cracking the engine block. When you are finally ready for the new coolant, USE DISTILLED WATER. Usually costs less than $1.00/gallon. You should drain the block also - it's the plugs down low on each side of the engine block, just above the oil pan rail. The knock sensor is usually screwed in at one of them. Sometimes those plugs can be stubborn to get out.
NoEmissions84TA is offline   Reply With Quote
Old 07-17-2018, 07:40 PM   #7  
Senior Member
iTrader: (1)
 
tom86iroc's Avatar
 
Join Date: May 2008
Location: pawtucket RI
Posts: 830
Car: 1986 iroc
Engine: alum. head 350 supercharged
Transmission: 6speed
Axle/Gears: ford 9in 3.90 35 spline moser axles


Re: temp gauge and radiator temp disagree

could also be were u mounted the sensors as to the different temps
tom86iroc is offline   Reply With Quote
Old 07-20-2018, 09:07 PM   #8  
Member
 
Join Date: Aug 2015
Posts: 103

Re: temp gauge and radiator temp disagree

Any time you up horsepower and compression ratio, you also need to update the whole cooling system. Doesn't matter slow cruise speed and RPM's.
Joe
JA411 is offline   Reply With Quote
Old 07-25-2018, 02:40 PM   #9  
Senior Member
 
l_dis_travlr's Avatar
 
Join Date: Jan 2006
Location: League City, TX
Posts: 710
Car: 90 Formula -- tot resto in progress
Engine: 350
Transmission: 700R4 w/ 2500 stall, by Owen @ ARD
Axle/Gears: 3.23 posi disc


Re: temp gauge and radiator temp disagree

Not clear from the thread what is really the problem. As you're driving around the neighbor hood, the temp is escalating, which is normal to a point. Does it ever reach a stable value? If so, what, as measure by trusted devices, like the laser temp gauge on the radiator core, or the rad cap gauge. I would use these as starting point to determine other issues, like sensors generating correct output. If the system is adequately clean, the stock v8 radiator may not be enough capacity under higher load conditions, like highway cruising, & or external ambient temperature, etc..

Hope this helps, keep us posted.
l_dis_travlr is offline   Reply With Quote
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
[NJ] B&M Trans temp gauge & B&M Water temp gauge new in the boxes.... jerzeydevil Interior Parts for Sale 2 03-06-2013 02:28 PM
TPI and Computer disagree's w/ Engine Hans Fud TPI 1 08-06-2010 06:43 PM
Is Coolant Temp. Sensor and Temp gauge Sender the Same? OddJack Tech / General Engine 4 05-22-2010 11:01 PM
friend claims Geo Storm is fast? i disagree. please read speedingpenguin Theoretical and Street Racing 29 07-01-2003 02:25 PM
Only temp gauge and RPM gauge works.. reborn92rs Electronics 0 05-07-2002 06:13 PM


Go Back   Third Generation F-Body Message Boards >

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Advertising
Featured Sponsors
Vendor Directory

1982 Camaro '82 || 1983 Camaro '83 || 1984 Camaro '84 || 1985 Camaro '85 || 1986 Camaro '86 || 1987 Camaro '87 || 1988 Camaro '88 || 1989 Camaro '89 || 1990 Camaro '90 || 1991 Camaro '91 || 1992 Camaro '92


All times are GMT -5. The time now is 06:31 AM.


© 2018 MH Sub I, LLC dba Internet Brands
We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: